QFileDialog not creates native File Dialogs correctly

I'm working on OS : Windows 7, Qtcreator : 4.5.0, Qt : 5.9.2.

When I debug the application in Debug mode or Run mode in Qt Creator, I'm experiencing bad rendering of the native file dialogs in QFileDialog. I tried QFileDialog::DontUseNativeDialog it is working. Unfortunately, customer wants native dialogs.

You can see some code snippet hereby.

bool saveAs()
    ProjectModel::AppSettings settings;

    QString fileName = QFileDialog::getSaveFileName(owner, tr("Save As"),
                                                    settings.lastSavedPath(),"*.tpp *.tpp2");

    if (fileName.isEmpty())
        return false;
    return saveFile(fileName);

When the program execute above lines it creates a Dialog with appearence issues like below.

enter image description here

Moreover, Save button won't work if I give a new name to save (I not a name of a existing file). But if I choose a existing name of a file the old file replaced by new one. And Cancel button is working too.

Apart from that I get several lines of this message in the console after that.

QImage: out of memory, returning null image

I found similar Question here and here but no any solution for me. I uninstalled any other Qt versions already because I thought that may be due to some confusion among versions.

Finally, Deployed app working perfectly. No issue of File Dialogs there.

Thanks for reading.